System of multiple pumps.



I P. J. GROUVELLE, E. H. AHQQEMBOUWG 81 L. I. FORET.

SYSTEM OF MULTIPLE PUMPS. APPLICATION FILED NOV- 18, I910.

Patented Jan. 30, 1917.

ffmzzucZle p WITNESSES PHILIPPE, JULES GROUVELLE, EMILE HENRI ABQUEMBQURG, AND LEON JEAN JORET,

or rams, rnnnon.

SYSTEM or MULTIPL PUMPS.

1,21&,300.

Specification of Letters Patent.

Patented J an. 30, 1917.

To all whom it may concern.-

Be it. known that we, P-HILIPPE JULES GRoUvELLE, EMILE'HENRI AR UEMBOURG, and LfioNJriAN JoREr, all 'of 71Rue du Moulin Vert, in the city of Paris, Republic of France, engineers, have invented a System of Multiple Pumps, of which the following is a full, clear, and exact description,

Among the various systems of pumps, the rotary, paddle or gear pumps are the only ones which theoretically give an outflow proportional to'their-number of revolutions. In fact, the piston pumps give, by reason of the inertia of the liquid in motion, outflows which increase more rapidly than the num-. ber. of revolutions; as regardsfcentrifugal pumps, they do not give any outflow below a certain number of revolutions.

' theoretical superiority of rotary pumps is counterbalanced "in practice by the possibility of suppressing the losses due to the necessary play between the members. This playpermits, of the return backward ofa certain portionfof the'liquidthat hasbeen forced back and so these pumps cease to when their speed, decreas.

ing, becomes such that their theoretical outflow forsaid speed becomes equal to the loss due to the play between the members. There are cases-where these. pumps must rotate at very variable speeds. and where the speed, at certain times, may-be very much reduced 1 and in certain applications it may cause 1nconvenience f the outflow does not remain proportionalto the number of revolutionsor even ceases completely.

5 Thejpresent invention has for its purpose to considerably lower the limit of speedfor which the outflow of a rotary pumpceases tob'e proportional to the speed of the latter,

. so that the reduced speedsat which the pump may bedriven remain above the said limit 4 and that thepump gives out proportionally limit value and, for

to its speed, in allthe conditionstor which is subiected. The diflerence between theoutflows of two adjacent pumps is; chosenin such a manner that, for thedetermined limit of-speed-belowwhich the'train of pumps will notbe lowered practically, this difi'erence 'is equal to the:

possible loss; in this'way ,the train of pumps can cease to proportionally give out only when the speed descendsjbelow' its lower any greater speed, the

normal working of the pump is insured.

.But. the 1 ripheries project.

the series, the liquid forced back through 19 passingat Q'and, being directly sent back by the latter, or through the medium of another or several other pumps up to the final forcing back; it will be understood that if the pump 9 must force back a volume Q and if, on the other hand, it can let a volume 9 escape toward the rear, on the suction side, the preceding pump 10 must be capable of giving out a volume P Q-l-g, for compensating the loss of the pump 9. Therefore the theoretical outflows increase by passing from one pump, to the adjacent pump toward the suction side, side toward the forcing side.

The difference between the outflows maybe obtainedin any suitable manner; the following means may be indicated by way of example: 1. All the pumps may be identical and have speeds slightly decreasing relatively toone another. 2. The pumps may have different diameters and they be actuated at the same speed. 3. The pumps may havethe same diameter and the same speed, but the penetration of the teeth progressively decrease. M 1

In the accompanying drawing'we illustrate. three different apparatuses for carrying out. our invention. Figure 1 is a sectional' and partly diagrammatic view of a pump comprising, a casing and two sets of ing teeth, their peripheries working in the may all Y the volumes displaced by and decrease from the suction longitudinal passage through which liquid flows, The first set of rotary members, in dicated by Z, z'- are rotated at a higher speed than the next or succeeding set, in dicated by Y, 3 the two being driven by a common motor X. The membersof each pair arejournaled on opposite sides of the passage, into which portions of their pe- All the rotary members are-in the same plane. Fig. 2 shows a modification in which the first set, of rotary have a greater diameter than the; next or succeeding set, indicated members D and d p it will be understood that D and D aredriven at'the same speed, but obviously the peripheries of the larger ones D and faster rate than the peripheries of the sucbylD= and d." Inother words,

ceedingset. "Fig. 31s, another modification 9 03' move at a ing into the passage from opposite sides,- the members nearest the outflow end of said passage being of lesser diameter'than the members of the-otherpair, and a'motor in which the first set of rotary members, to

' wit, E and e, are driven at the same speed as the succeeding members, F and f, but the volume of water displaced by the first set is greater by reason of the fact thattheir teeth are larger or longer.

What-we claim is l 1. The improvement in multiple rotary pumps of the class indicated, comprising a casing having a central passage, a series of 'pairs of circular rotary members journaled oppositely to each other and on opposite .sides of said'passage' into which they proje'ct, all being in the same plane, the 'members' of ,each pair working in peripheral contact, and a' motor-[which is geared with both pairs, the two members adjacent to the delivery side of the pump operating to,

produce an outflow less than that of the pump on the suction side, as described.

v 2. In a multiple rotary pump of the class described, the combination with a casing having a central passage, of two series of pairs of circular rotary members working in peripheral contact and arranged in the same plane with their peripheries. projectgeared with both pairs and" rotating them at same speed, as'de scribed.

3. A multiple pump of the rotary type indicated, comprising a casing or covering v rotary members arranged in said casing,

havinga central passage, pairs of circular -each pair constituting a unit-pump and the members of each pairv arranged rotatably i opposite each other on opposite sides of said passage; and projecting into the latter so that their. peripheries work-in contact, and means forgiving the unit-pumps dif ferent peripheral speeds so that the dis? 1 7 charge of one is higher'than pump it feeds, as described.

4; A multiple rotary pump of the class described, comprising a casing having ;a

central passage, a series of pairs of circular rotary members, each pair constituting a that p of 'jthe that of'thepum'punit which it feeds accordingto the losses ofthe latter.

"described, comprising a casing having a centralpassage, a series ofpairs of circular -rotary members, each pair constituting a pump unit, the members of each pair rotating oppositely toeach other, being arranged on opposite sides of said passage into which they project and working in peripheral contact, all being in the;same plane, the rotarymembers constituting two successive pump units having diiferent diameters such that the outflow of each pump unit be greaterthan that of the'pump unit which [it feeds according to the'losses of the lat- I ter, and a motor geared with the pairs of rotary m'embers.

. 6,; :A liquid pumpof the type indicated, comprising a casing provided with a central passage, two pairs of circular rotary outflow ofeach pump unit be greater than i' 5 A multiple rotary pump of the class pumps proper, the said pairs arranged in series and theperipheryof each pump projectingintosaid passage and working in peripheral contact with the opposite member off'the 'pair, andmeans for rotating the several pumps as described, whereby the has anf'outflow greater than that of the pump nearest the outflow side,

.'-The foregoing specification of our system of multiple pumps-signed 'by' us this 10th da'y; ofOctober, 1910.

YPHILIPPE JULES'GROUVELLE; EMILE HENRIARQUEMBOURG. LEON JEAN JORET I Witnesses:

H. O. Come, R. EHIRIOT.-

pump nearest the suction side of the casing 

